In total, 50 Rhizobium isolates were isolated from the mature root nodules of common beans plants (Phaseolus vulgaris) grown in different nine governorates of Egypt. PHB was optimized by the identified strain using response surface methodology. A total of 11 parameters (pH, incubation period, inoculum size, temperature, agitation speed, mannitol, sucrose, yeast extract, glycine, K2HPO4, and MgSO4) were analyzed for their significant effects on PHB production by the Plackett–Burman design (PBD). Sucrose, yeast extract, glycine, and MgSO4 were the main significant factors affecting PHB accumulation. Central composite design (CCD) of the response surface methodology was used to determine the optimum levels of the selected factors. Rhizobium phaseoli reached the maximum production (4.997 g/L) at run 36 in the presence of 25 g/L of sucrose, 0.0 g/L of yeast extract, 0.87 g/L of glycine, 0.3 g/L of MgSO4, and 5% of inoculation size. In vitro experiments were carried out to test the effect of different stress conditions (pH: 6–11, temperature: 5°C–50°C, salinity: 0.01%–7%, and drought: 0%–5% w/v) on the growth of Rhizobium phaseoli. The results showed that Rhizobium phaseoli can withstand 3% –5% NaCl, high temperature of 30°C– 45°C, alkalinity at pH value of 8 – 10, and drought stress at 3% – 5% w/v polyethylene glycol with growth loss of 50% when grown on modified medium and 75% when grown on the basal one. In vivo experiments were done to study the effect of drought stress levels on the growth parameters of common bean plants. In general, all the treatments with Rhizobium phaseoli grown on the modified medium were superior to Rhizobium phaseoli grown on the basal medium. Also, they showed high tolerance of drought conditions.

Wheat is an essential staple food in the developing world, where demand is projected to grow exponentially in the future; simultaneously, climate changes are projected to reduce supply in the near future. One of the main consequences of climate change is salinity, which negatively impacts the world's cultivated area and therefore affects the global wheat production. Our objectives are to study the population structure of several Egyptian and international wheat accessions and to identify the genetic factors controlling the salinity stress response of bread wheat. In addition, we have attempt to identify genes that control some important agronomic parameters of wheat under salinity stress were identified. The wheat germplasm panel consisted of 70 accessions obtained from Egypt, Syria and Iran. The assessment of salinity tolerance was conducted over the years of 2018 and 2019 in the field and in the greenhouse. The genome association analysis (GWAS) and population structure analysis was conducted using six SCoT, five SSR and 93 SNP markers. Analysis of the population structure using allele frequency and phylogenetic analysis indicated that the studied wheat accessions were belong to four population groups. Where, for the most portion, Egyptian, Syrian and Iranian accessions are clustered depending on their country of origin. The GWAS analysis revealed 13 SNP markers that were significantly associated with morpho-agronomic wheat traits during salinity stress. These markers were closely related to genes that are known to have a direct link to wheat response to salinity stress such as CYP709B2, MDIS2, STAYGREEN, PIP5K9, and MSSP2 genes. This study revealed the genetic structure of adapted and imported wheat accessions, which could be used to select potential wheat accessions for local breeding programs. In addition, the SNP genotyping assay is a very potential technology that could be efficiently applied to detect genes that control bread wheat response to salinity stress.

Salinity is a major limiting factor for tomato crop growth and productivity especially in arid and semi arid lands region. Therefore this study was conducted to study the effect of applying sugar beet molasses, priming tomato seedling in saline water and Fe-EDHHA on mitigating salinity negative effects on tomato (Lycopersicon esculentum L.)  hybrid super strain B (salinity sensitive hybrid). Seedlings of tomato hybrid were transplanted on April 4th in both seasons 2014 and 2015 in pots contains washed sandy soil, and irrigated with saline water with EC of  2000, 3000 and 4000 ppm. Beet molasses and Fe – EDHHA were applied at  rates of 200 and 300 kg / fed. for beet molasses and 3 and 4 kg / fed. for Fe – EDHHA. Priming tomato seedlings in saline water treatment was applied at 5 and 6 dS/m for 24 hours.  Data showed that all plant growth aspects such as plant height, leaf area, plant fresh and dry weights were improved under beet molasses, Fe and priming tomato seedlings in saline water treatments compared to none treated plants (control). Yield parameters also followed the same trend. Among treatments, beet molasses at a rate of 200 kg / fed. recorded the highest significant effect in mitigating salinity negative effects. It could be concluded that beet molasses, priming tomato seedling in saline water and Fe – EDHHA treatments were more effective and efficient in mitigating salinity stress on tomato plants.

This study was carried out to investigate the effect of saline water irrigation at 2000, 4000, 6000, 8000 and 10000 ppm by using a mixture of two salts (sodium chloride: calcium chloride, 2:1, w/w)  in addition to tap water  as control and foliar sprayings of Salicylic acid (SA) at 100, 200 and 300 ppm in addition to tap water as control on growth, flowering and chemical composition of pot marigold plants in the two successive seasons of 2014/2015 and 2015/2016 in the Faculty of Agriculture, Ain Shams University, Qalyubia Governorate, Egypt. Results revealed that all tested foliar applications of SA increased all vegetative growth characteristics (plant height, number of leaves /plant, leaf area, number of branches/plant, diameter of stem, fresh and dry weights of vegetative growth and roots, and roots volume), and flowering attributes (number of inflorescences/plant, diameter of inflorescence, fresh and dry weights of inflorescences). While, saline water irrigation decreased growth, flowering parameters, chlorophyll, carotene contents in flowers and some minerals contents of the vegetative growth, i.e. nitrogen, phosphorus and potassium percentages. However, saline water irrigation increased proline and some mineral contents, i.e. calcium, sodium and chloride percentages of the vegetative growth. In most cases, under the same saline water irrigation conditions spraying SA at 100 and 200 ppm concentrations alleviated the salinity effect on the plants, enhanced the plant growth and increased the flowering parameters. The most effective treatments which enhance growth, flowering parameters, chlorophyll content, carotene contents in flowers, proline and mineral contents were found to be 100 and 200 ppm SA spraying under nonsaline conditions.

A greenhouse pot experiment was carried out to investigate the effect of salinity and potassium at different levels alone or in various combinations on growth, mineral and proline content in leaves of plantlets of Phoenix dactylifera L. cv. Bartomouda (in vitro production, two years old from acclimatized them). The following treatments were applied: three levels of salinity Na Cl + Ca Cl2 w.w 2:1 (14000, 16000 and 18000 ppm.) and two levels of potassium (2000 and 3000 ppm) in addition to control (no salts or potassium used), salts and potassium were added in the irrigation water. In general, all levels of salinity significantly decreased various growth parameters such as plant height, number of leaves and roots, root length, fresh and dry weights of leaves than that of the control. These parameters were decreased with increasing salinity levels, whereas it, significantly increased Na, Ca and K contents in leaves with high content of proline. The treatment 18000 ppm salts gave the highest significant reduction of the growth parameters, while caused an increase in proline Na, Ca, and K contents compared to control treatment (no salts) . This was true in both seasons. The applications of potassium significantly increased the previous growth parameters as compared with the control treatment (without salts and potassium) the treatment 3000 ppm had the highest results. Moreover the applications of potassium gave high alleviated the negative effects of salt stress, the treatment 3000 ppm gave the best results on the growth parameters of date palm plantlets grown under salinity condition . Regarding the interaction the obtained data revealed that the interaction between treatment 3000 ppm potassium and 14000 salts produced the highest significant results. Generally, from the obtained results it can conclude that the plantlets of date palm produced by tissue culture can be tolerated salt stress by addition of potassium which can significantly ameliorate the harmful effects of salts, positive effects on the growth parameters of the plantlets was showed by potassium applications.

Two pot experiments were carried out during the summer seasons of 2006 and 2007 to investigate the effect of irrigation with diluted saline water; i.e., 10, 30 and 50% in addition to Tap water as a control on growth, chemical composition, yield and tuber quality of three new sweet potato cultivars (Minufiya 6/96, Minufiya 2/96 and Minufiya 171/96) as well as the local cultivar (Mabrouka). The obtained results revealed that, saline water at 10 and 30% levels stimulated growth of sweet potato plants represented by plant height, number of leaves and branches, dry weight of shoots as well as the contents of photosynthetic pigments, proline, total carbohydrates, N, P, K+ and Ca++ in sweet potato leaves were also increased. Moreover, total water content (TWC), bound water (BW), bound / free water ratio (BW/FW) and relative water content (RWC) increased under these conditions. All these parameters decreased at the level of 50% salinity. Yield and its quality significantly increased at saline water at 10% level. Also, chemical composition of tuber roots; i.e., total carbohydrates, soluble sugars, carotene, starch and dry matter contents were enhanced under these conditions. All previous parameters decreased with increasing saline water up to 50%. Saline water levels increased Na+ content in the leaves. As for the tested cultivars, generally Minufiya 6/96 had the best growth and yield, was more stable in the chemical components and its roots had the highest nutrients value under the control and salt stress conditions, followed by Minufiya 2/96 then Minufiya 171/96. The tuber roots yield of Mabrouka cultivar was completely depressed at 30 and 50% salinity levels. As for interaction between cultivars and salinity levels. The highest level of salinity (50%) lead to a significant decrease in all growth parameters, RWC, TWC, bound water (BW), bound water / free water (BW/FW), chemical composition, yield and its quality in all new tested cultivars. While, Mabrouka cultivar showed a significant decrease in these parameters under the all salinity levels. Accordingly, Minufiya 6/96 was the highest tolerant to the tested salinity stress, followed by Minufiya 2/96 and Minufiya 171/96. On the other hand, Mabrouka cultivar sensitive to salinity.